The Role of Microtexture on the Fatigue Behavior of an alpha + beta Titanium Alloy, Ti-6Al-2Sn-4Zr-6Mo (Preprint)

Abstract

The effect of microstructural heterogeneity, specifically regions of grains with similar crystallographic orientations, or microtexture, on the initiation and early growth of fatigue cracks from multiple micro-notches has been investigated in Ti-6246. Experiments were performed using ultrasonic fatigue techniques for two different microstructural conditions. Local texture surrounding micro-notches was found to influence micro-notch fatigue crack initiation in one of the microstructures. Fatigue crack initiation was least likely to occur from notches placed in neighborhoods with a microtexture unfavorably oriented for easy basal slip. However, small fatigue crack propagation rates were not influenced by the microtexture in these local neighborhoods. A systematic variation in micro-notch length indicated that fatigue cracks initiated from naturally occurring microstructural features when micro-notches with a surface length (2c) less than 15-20 μm were machined in specimens.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2011
Accession Number
ADA548142

Entities

People

  • C. J. Szczepanski
  • J. W. Jones
  • James M. Larsen
  • Sushant K. Jha

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Alloys
  • Crack Propagation
  • Crack Tips
  • Cracks
  • Grain Boundaries
  • Grain Size
  • Heterogeneity
  • Materials
  • Materials Science
  • Mechanical Properties
  • Microstructure
  • Stress Intensity Factors
  • Titanium
  • Titanium Alloys
  • Ultrasonic Frequencies

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
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